$8x-75=5x+21$
$⇔8x-5x=21+75$
$⇔3x=96$
$⇔x=32.$
$Vậy...$
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$9x+25=-(2x-58)$
$⇔9x+25=-2x+58$
$⇔9x+2x=58-25$
$⇔11x=33$
$⇔x=3.$
$Vậy...$
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$|x+3|=4$
$⇔\left[ \begin{array}{l}x+3=4\\x+3=-4\end{array} \right.$
$⇔\left[ \begin{array}{l}x=1\\x=-7\end{array} \right.$
$Vậy...$
--
$15-|2x-1|=|-8|$
$⇔15-|2x-1|=8$
$⇔|2x-1|=7$
$⇔\left[ \begin{array}{l}2x-1=7\\2x-1=-7\end{array} \right.$
$⇔\left[ \begin{array}{l}2x=8\\2x=-6\end{array} \right.$
$⇔\left[ \begin{array}{l}x=4\\x=-3\end{array} \right.$
$Vậy...$
